Question

我正在尝试使用@ManagedProperty注释在JSF ManagedBean中使用spring Container中创建的bean。但是在使用该bean时我得到空指针。一旦启动我的服务器，我就可以看到我的bean被创建了这里

Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@9d532ae: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,userBean,userService];

HomepageBean.java

package come.test.backingbean

 @ManagedBean
    @sessionScoped

        public Class HomepageBean{

        @ManagedProperty(value="#{userBean}")
        private UserBean userBean;// getters and setters


       public String doLogin() {
            String url = "login.xhtml";
            LoginBean manager = new LoginBean();  // This bean has a condition which check for Username and password entered by user.
            if (manager.auth(username, password)) {
                isLoggedIn = true;
                url = "homepage";
                String username=sample;
                userBean.getUserInfo(username);
            } else {
                FacesContext context = FacesContext.getCurrentInstance();
                context.addMessage(username, new FacesMessage(
                        "Invalid Username and or Password"));
            }
            return url;
        }

UserBean.java

package com.test.mypackage

@Component
Public Class UserBean{

@Autowired
private UserService userServie  // getters and setters.

     public void getUserInfo(String userId){
      userService.findByUserId(userId)
 }
}
}

UserService.java

package com.test.service;

public interface UserService {

    public void save(User User);
    public void update(User user);
    public void delete(User user);
    public User findByUserId(String userId);

}

我可以看到我的服务器启动时我尝试使用的bean是预先实例化的。我在applicationContext.xml中将web.xml定义为Context-param。我正在定义Spring.xml中的所有bean，就像这样

spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

<context:annotation-config />

<context:component-scan base-package="com.test" />

<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>

</beans>

位于我的类路径中，并将其作为资源导入applicationContext.xml。

的applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:security="http://www.springframework.org/schema/security"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <import resource="classpath:database/DataSource.xml" />

    <import resource="classpath:database/Hibernate.xml" />

   <import resource="classpath:config/Spring.xml" />

</beans>

my faces-confi.xml

<application>
   <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
    <resource-bundle>
        <base-name>com.test.boundles.messages</base-name>
        <var>msg</var>
    </resource-bundle>
    </application>

我的方法有任何问题。

Answer 1

应该更好地处理多项事情。

1）您只需要<context:component-scan base-package="com.test" />，删除annotation-config和AutowiredAnnotationBeanPostProcessor。

参见原因：Difference between <context:annotation-config> vs <context:component-scan> 和Documentation

2）你的UserBean没有范围，如果你没有提到任何范围，默认范围将是Singleton，在这种情况下我认为不合适。

3）您正在尝试使用接口而不是实现此接口的可实例化类。

4）然后，您应该将实现类标记为@Service以进行自动装配。

5）我希望你有吸气剂和制定者，而不仅仅是那些评论。

有关示例，请参阅此link

另见：

@Scope("request") not working

从具有JSF @managed属性的spring Container调用预实例化bean时的空指针

1 个答案: